Do you think microbes can also be used as source of energy? If yes, how?
Yes, microbes can be used as a source of energy. Certain bacteria called methanogens produce biogas, which is a mixture of gases containing predominantly methane. These bacteria grow anaerobically on cellulosic material and produce large amounts of methane along with CO₂ and H₂.
Methanobacterium is a common example of methanogen. These bacteria are commonly found in the anaerobic sludge during sewage treatment and are also present in the rumen of cattle, where they help in degrading the cellulosic material present in cattle's food.
The biogas produced by microbial activity is used as a source of energy in rural areas. Methanogens produce methane while degrading plant waste, making this a practical application of microbes as an energy source.
Explanation
This 3-mark answer addresses the question by first confirming that microbes can indeed be used as an energy source. It then explains the mechanism - methanogens producing biogas (methane) through anaerobic decomposition of cellulosic waste. Key terms from the textbook include methanogens, Methanobacterium, biogas, anaerobic sludge, and rumen. The answer connects the biological process to practical application in rural areas.
Solution Steps
Step 1: Confirm yes - microbes can be used as energy source
Step 2: Explain mechanism - methanogens produce biogas (methane) anaerobically from cellulosic material
Step 3: Provide examples - Methanobacterium found in sewage sludge and cattle rumen
Step 4: State application - biogas used as fuel/energy in rural areas